How to Knock a Load-Bearing Wall in the UK
- Real Life Architecture
- Nov 17, 2025
- 7 min read
Back in 2024, I made a video explaining the cost to remove a load-bearing wall. I based it on a project in Edinburgh, where I had two contractors price the job, so the costs were accurate. That video continues to be popular on my channel, but I never really went into detail about how the wall was demolished. So in this blog post I am going to show you how it's done, step by step.
I'm not making this so that you can attempt to knock a wall yourself. Really, please don't do this at home.
I’m making the video because you have a choice when taking down a load-bearing wall that will significantly affect the cost of the work, so stay tuned for that. I am also writing this post to dispel concerns some people have about load-bearing walls. I’ve spent my career altering and extending private homes and have lost count of the number of homeowners who worry about doing this type of work. For the average person, who might never have set foot on a building site, knocking a load-bearing wall might seem very risky, like open-heart surgery. But for people in the construction industry, it's more like getting stitches; it's not risk-free, but it is an unremarkable everyday operation. Maybe, once I've shown you how this is done, it will dispel any worry you have about demolishing a load-bearing wall. So let's start by asking,
How do you identify a load-bearing wall?
Given the variety of styles, ages and methods of construction across the UK, internal walls can be complex, and it is never safe to assume the method of construction determines the structural status of a wall. It is possible to have brick partitions that don't carry any load and timber frame walls which do, and sometimes in the same building!
Older properties can have more than one type of partition wall, especially if the building has more than one floor. The lower floors might have brick partitions but the top floor could have timber stud walls between the rooms. Things can get even more complex if previous owners made changes to the house. I’ve seen Victorian and Georgian homes with brick, block, timber stud and metal frame partition walls, all in the same property!
You should always assume that internal partitions have some load-bearing capacity, no matter what they are built from. But in this video, I am going to look at taking down a brick wall because these are widespread, especially in older properties. Your home might be different and when doing this work for real you will always need a structural engineer. I will explain what the engineer does later in the video but first we should ask
Do you need permission to knock a load-bearing wall?
The short answer is, yes. Taking down a load-bearing wall requires building regulations approval. You might think this is purely a structural issue, but it can be much bigger than just specifying the right steel beam. The building regulations consider other factors. Imagine joining two rooms together. One room has a window, and the other room does not. For a room to be legally habitable, it must have a minimum amount of natural light and ventilation. That window might be only just large enough to comply at present, but if you enlarge the room, the window won't be big enough.
Issues like this can massively impact a project. You should always take professional advice to look at the bigger picture before doing anything like this.
If you want to speak to me, I offer an online consultation service for homeowners and buyers anywhere in the UK
How to Demolish a Load-Bearing Wall
Let's assume you own a typical two-storey house in the UK. It dates from the mid-20th century, the internal walls are made from brick and you want to join two rooms together by taking down this wall, how do you do it?
Let's assume you commissioned a structural engineer and they produced drawings and specifications like these.
They specify the new beam that will hold up the wall above, and they also provide a methodology for the builder, explaining how the wall is to be supported during the work.
The builder starts by making a series of holes in the wall, just below the ceiling. They knock out some bricks and then they set up Acrow props, one on each side of each hole.
A builder can use short steel sections like these. They are called needles and they are placed through the holes and connected to the top of each Acrow prop.
The Acrow props are telescopic; they can be adjusted up or down using threads, just like a bolt. Doing this, the builder can push the needles up until they touch the bricks in the wall above. Once every needle is level and securely propped, the wall is supported and the bricks underneath can be removed.
I know this looks weird; Why does the wall above not fall just down through the gaps between each needle? The answer is that the load does not transfer straight down; it runs at an angle. That angle will change depending on the type of brick bond in the wall. This can vary from 30 to 45 degrees, depending on the type of bond the wall was built from.
If you imagine an invisible 45-degree line spreading out from each needle, bricks above the invisible line are supported on the needles. Bricks under that line are effectively free-standing, held together with nothing more than mortar. The closer together the needles, the fewer bricks are free-standing and the wall will stay up. The structural engineer has to determine the gap between the needles in their calculations.
Once the needles are installed, the builder fits a dense concrete block on each side of the new opening in the wall. These are called pad stones, and the new steel beam rests on them. That beam might be heavy and builders often use hoists or lifts to manoeuvre beams into place. But once that beam has been installed, new bricks are laid on top, until they connect with the underside of the original bricks in the wall.
The new beam must be left in place, with the Acrow props still supporting the wall for about one week. This is to make sure no cracks emerge upstairs. After that, the builder carefully releases the pressure on the Acrow props and removes the needles. They fill in the holes with new brick and that’s it, the load-bearing wall has been removed.
The downside is that the new steel beam holding up the wall must be installed underneath the needles. It can be covered in plasterboard for fireproofing but it will be visible in the finished room as a flat arch or bulkhead. You could choose to build a false ceiling lower down, to hide the beam but there are alternatives. There are thin needles, such as Prop Pal, made specifically to get the new beam as close to the ceiling as possible. This is where the homeowner has a choice to make that will affect the cost.
If you really do not want to see that beam in the finished space and you really don't want to lower the ceiling to hide it, there is a solution. The needles can be formed in the rooms above, but that will destroy the floor and increase costs.
Obviously, this isn't feasible if you live in a flat with upstairs neighbours. But if you have a house and are willing to spend extra, this is an option.
If the wall you want to demolish is next to a party wall, the new beam pad stone can't be cut into that party wall because that might compromise its fire and acoustic separation with your neighbour's property. In this situation, a steel post can be fixed on your side of the party wall to carry the new beam supporting the load-bearing wall. Sometimes, if the span of the new beam is above a certain size, the engineers will specify a steel post on both ends.
This is referred to as a goal post arrangement, and the posts usually require their own foundation pad, which can drive up the cost. Keep that in mind if you want to form larger openings. And if you want to form an opening in an external wall, more than one steel beam is usually required.
In older buildings with stone walls, like this one, the engineers will specify a picture frame arrangement, with posts at each side and beams buried in the floor. This is extremely strong and is usually done if the property has neighbours adjoining. The picture frame may be expensive, but it prevents movement in the new structure from sending cracks through your neighbour's property.
Another factor that can increase costs, is if your house has a suspended timber ground floor. If you are taking down a load-bearing wall, that floor will probably not be strong enough to support Acrow props. Structural engineers have told me that suspended timber floors are usually designed to carry no more than 150 kilos per square meter. Acrow props would concentrate the load from the wall above onto a small area, and the floor would fail.
While it might be possible to spread the load using timber beams, a safer method is to cut holes in the suspended floor and stand the Acrow props on the solid floor underneath. But keep in mind that repairing the floor will increase the overall cost of the project.
Summary
Like I said at the beginning, while this might seem complex and risky, taking down load-bearing walls is something every builder does. Engineers and Architects understand this type of work well, and no matter how complex the job, we will have a solution.
Keep in mind that structural work on its own is often not the highest cost. The remedial work to the surrounding floors, walls and ceiling, as well as any drains, pipes or wires, can cost more than the new steel beams. Over recent years, the cost of insurance in the construction industry has risen significantly. One area where this might impact you is getting a structural engineer to design new beams when taking down load-bearing walls in a block of flats. I do a lot of work to Victorian tenements and Georgian apartments in Edinburgh and several local engineers won't touch this work, because it would drive up their insurance premiums. Taking down a load-bearing wall in a flat has the potential to send a crack running up through the building, and claims from neighbours could be expensive. It hasn't happened on any of my projects, but it has increased the cost of engineering services.
If you want to talk about this, or any other type of work to a property anywhere in the UK, you can book an online consultation with me through the Real Life Architecture website.
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